Species identification of raw and cooked bivalves using electrophoresis

Three electrophoretic techniques, isoelectric focusing (IEF), sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and urea-IEF were used for species identification of "baby-clams" from Vietnam (Meretrix lyrata), grooved carpet shell (Ruditapes decussatus) and the common edible cockle (Cerastoderma edule). Analysis were performed on proteins extracted from different parts of the mollusks, adductor muscle. mantle, foot, of raw and cooked samples. The electrophoretic patterns of adductor muscle were the most discriminative. Although all three methods tested could be used for bivalve species identification, the electrophoretic profiles with IEF were modified after cooking, whereas those with SDS-PAGE or urea-IEF were identical in raw and cooked samples and thus more suitable for sample authentication.